The
Washington
State
University
Tree
Fruit
Research
and
Extension
Center
provides
a
calculator
for
estimating
water
use
by
plants
or
pET
(potential
evapotranspiration).
Water
use
varies
widely
from
plant
to
plant,
so
estimates
are
usually
first
derived
for
a
single
situation,
such
as
grass,
and
then
adapted
for
other
plants.
The
calculator
uses
the
Penman
method
to
estimate
daily
pET
in
inches
of
...
Full description.

Grade level:
College (13-14), College (15-16), Graduate / Professional

This
website
is
the
official
time
clock
for
the
United
States.
Users
choose
from
a
variety
of
time
zones
(Marshall,
Micronesia,
Palau,
Guam,
Samoan,
Hawaiian,
Alaskan,
Pacific,
Mountain,
Central,
Eastern,
Atlantic
or
UTC)
and
view
the
current
time
in
that
zone
along
with
a
map
showing
day
and
night
across
the
world.
A
world
time
zone
map
is
included
for
reference.
Links
are
provided
to
other
time-related
...
Full description.

SunAngle is an on-line tool that calculates solar angles and related information for a given location, date, and time. It computes the declination of the Sun, sunrise and sunset times, azimuth of the Sun, solar time and more. Complete instructions and definitions of variables are included.
Full description.

Grade level:
College (13-14), College (15-16), Graduate / Professional, General public

This website provides calculation tools for conversions of length, area, and degrees to radians. Map conversions include a map scale calculator, and conversions from degrees, minutes, and seconds to decimal degrees (and vice-versa).
Full description.

Grade level:
College (13-14), College (15-16), Graduate / Professional

This applet allows users to see what the elevation, noon elevation, and azimuth of the Sun is for specific locations (requested by city or latitude and longitude) and time zone for the current date. This program also shows how long the Sun will be above or below the horizon for the current date and the location the user chooses.
Full description.

Grade level:
College (13-14), College (15-16), Graduate / Professional, General public

This applet is designed to show the user the current positions of the Sun and Moon, as well as locations of day and night, on a map of the Earth. The Moon phase as well as Sun declination are indicated on the map. A downloadable demonstration of this applet is available.
Full description.

This applet shows the current (realtime) Sun position as seen from a polar view above the North pole. The elevation and azimuth of the Sun are given, and a brief description of celestial coordinates and celestial spheres is covered as well. A demonstration of this applet is available to download.
Full description.

Grade level:
College (13-14), College (15-16), Graduate / Professional, General public

This
applet
calculates
the
approximate
times
of
sunrise
and
sunset
from
a
geometrical
construction
for
any
location
and
date.
Users
can
select
their
locations
from
the
menu
list,
enter
the
coordinates
manually,
or
click
into
the
right
half
of
the
circle
to
set
the
latitude.
Month
and
date
are
chosen
from
the
menus.
There
is
also
a
summary
table
that
compares
the
applet's
values
to
those
calculated
...
Full description.

This units conversion tool for science students and scientists allows users to enter a numerical value and a permissible unit (or select from a menu) and subsequently select the "wanted" unit from another menu. There is a separate tool for temperature conversions. It is also available in German.
Full description.

Grade level:
High (9-12), College (13-14), College (15-16), Graduate / Professional

This world population clock is an applet that uses a logarithmic equation obtained through a statistical analysis of data from the U.S. Bureau of the Census. The clock takes into account both births and deaths. You can compare the current world population to any date since 1970.
Full description.